The Environmental Transport of Radium and Plutonium: A Review

It has been estimated that since the dawn of the nuclear era more than “73 million cubic meters of soils and sediments in the U.S. alone have been contaminated with actinides and fission products by Department of Energy defense nuclear activities.” However, with respect to the protection of human health, the most relevant question is not how much radiation is in the ground, but how much radiation will eventually reach people and damage living cells. In order to answer this question it is necessary as a first step to predict the transport of the contaminants from where they leaked or were discharged through the environment to areas where humans may be exposed to them. The second step is to then try to predict how much of that radiation people would be exposed to, and thus how big a dose they would receive. In this report we will consider only the first step in this process. There are a number of routes of exposure and transport, such as (1) resuspension of deposited radionuclides into the air, (2) uncovering of buried radionuclides due to erosion and subsequent exposure to gamma radiation, (3) migration of radionuclides into groundwater, and (4) mobilization of radionuclides by erosion into surface water. This report provides a review of the last two mentioned pathways, which impact the purity of water resources. It is further focused on two elements, radium and plutonium, that are present at many contaminated sites across the United States and in other countries as well.